1. Technical Field
The present invention relates to a communication apparatus that communicates data over a network, among communication apparatuses that communicate data.
2. Related Art
An Internet facsimile that transmits a fax image to a transmission destination apparatus by attaching the fax image to an e-mail has been standardized by the International Telecommunication Union Telecommunication Standardization Sector (ITU-T). In the Internet facsimile, since the fax image is attached to the e-mail, it is possible to transmit the fax image to a transmission destination apparatus over a network. Examples of a transmission method of an e-mail in the Internet facsimile include a mode (a simple mode, or a full mode) of transmitting an e-mail to a counterpart apparatus through a mail server, and a mode (direct SMPT) of directly transmitting an e-mail to a transmission destination apparatus without passing through a mail server.
In the full mode of the Internet facsimile, a request for an acknowledgement response may be given to an e-mail for confirming whether or not the e-mail is successfully delivered to a transmission destination apparatus. An apparatus that has received the e-mail having the request for an acknowledgement response notifies that the delivery of the e-mail has been completed, by performing a process (acknowledgement response) of returning the e-mail to a destination that is designated by the request for an acknowledgement response (for example, see JP-A-2003-258933).
If an apparatus responds to all requests for acknowledgement responses, acknowledgement responses are transmitted even to transmission source apparatuses that the user does not intend. For example, the acknowledgment responses are made for e-mails that are indiscriminately delivered from the transmission source apparatus, resulting in that the destination of the transmission destination apparatus is known to the user of the transmission source apparatus.